Malachai fight script stops if you ignite Piety

I attacked Piety with Firestorm when she asked me for it the first time, igniting her. She lost a lot of health, but Malachai didn't drop his shield and remained invincible, Piety just stood around doing nothing. The fight continued only when I died or used a portal, went to town and came back (I had the bug both on normal and cruel and tried both). Not sure how exactly that was triggered, probably because Piety reached her threshold by DoT and not a hit.

This was reported a few times, but it seems that you've noticed something that wasn't obvious from other reports (well, not the thread topics). You may be onto something with that ignite damage causing it, cause I burned her a bit too and got the same thing. Sadly I do not have the exact moment of this happening recorded, only whatever happened later (to show that I can actually deal some further damage to her, but it seems only by burning - hits do not count at all). I'm currently encoding a vid to upload it to youtube. Will edit in a second. It's super-boring, but perhaps devs can get something from it. Also, I did /bug and my bug number is 2 931 634 388.

Edit: Youtube says: Your video will be live at: https://youtu.be/2HK6QML6_uA